[beagle3]

They are supposed to be about a particular implementation, but the USPTO awards then for ideas (stuff like "treat years less than 50 as 19xx and above 50 as 20xx" and LZW, which are each implementable in many ways).

Courts assume the USPTO is competent, so overturning a patent is extremely costly. The bottom line is: practically speaking, ideas are patentable but without complete certainty of prevailing in court.

[sitkack]

Not only are ideas patentable, just recognizing a need or problem is patentable. One doesn't even need a solution.